Improve input device wake heuristics.

Bug: 5205674

Only wake the device on positive interactions from the user
such as button presses, movement, initial touch down events.
In particular, do not wake the device on up events since the
driver might synthesize them on power off, causing the device
to wake up again for no good reason.

Change-Id: I767f553ea36d110e6f3a10611b324487ba7d880d